Conventional acrylonitrile-butadiene-styrene copolymer resin (ABS resin) is used in various applications such as automobile parts, home appliances, toys, and the like because of the hardness and chemical resistance of acrylonitrile, impact strength of butadiene and processibility of styrene, and beautiful appearance. Conventional ABS resin, however, cannot typically be used in application requiring transparency because the ABS resin is opaque. Accordingly, there is a need for a transparent resin.
Examples of transparent resins used in products that require transparency can include styrene-acrylonitrile copolymer resin (SAN resin), polycarbonate resin (PC resin), general-purpose polystyrene resin (GPPS resin), poly(methyl methacrylate) resin (PMMA resin), transparent acrylonitrile-butadiene-styrene copolymer resin (transparent ABS resin) and the like. Transparency can be imparted to ABS resin by minimizing light scattering and refraction at the interface of the dispersed-phase and continuous-phase by matching the refractive index of the dispersed-phase rubber-modified polymer with the refractive index of the continuous-phase SAN resin matrix. Also, transparent ABS resin can have high impact strength and excellent processibility compared with other transparent resins.
European Patent No. 0703252 is directed to a method for imparting transparency to high-impact polystyrene resin. The resin, however, can have deteriorated chemical resistance and scratch resistance.
Although there have been efforts to develop a transparent ABS resin having relatively high chemical resistance and scratch resistance, most of these resins attain just 2B or 3B pencil hardness.